George W. Bush may have been wrong about a lot of things, but he was right about this: The president is the decider.

Except, it seems, when he isn't. Because President Trump is very clearly not the decider. White House Chief of Staff John Kelly is.

Presidential advisers always exercise a lot of power — by controlling and shaping the information a president receives, by helping him to make informed and well-considered decisions. But everyone understands that the "buck stops" at the president's desk in the Oval Office. He is the head of the executive branch. He is the person entrusted with the authority to decide what gets done and what doesn't, from setting policy priorities for the executive branch and Congress to deploying American troops around the world and even, potentially, launching a nuclear attack that kills millions.

The situation in the Trump administration is vastly different. The man who occupies the office is utterly ignorant of policy and even of the way the government and the international order function at an elemental level. His attention span is reportedly so limited that the briefing books typically given to presidents prior to meetings must be condensed to lists of highly simplified bullet-points. He places greater trust in Fox News as a source of information than he does in the federal agencies empowered to provide him with detailed intelligence about the state of the world. He's prone to emotional outbursts that color his policy preferences and goals, leading them to change drastically from day to day and sometimes hour to hour, and that could well shape his decision-making about matters of war and peace.

All of this vastly elevates the importance of the people surrounding President Trump. If his advisers don't tell him something, or if they significantly edit the information he's given about an event or his range of options on a given issue, he will almost certainly lack the capacity to recognize the omission or marshal contrary evidence to push back. The statement "Really? That doesn't sound right to me" will never be uttered by this commander in chief.

In the opening months of the administration, the result of this utter incapacity at the top was near-total chaos, as a weak chief of staff (Reince Priebus) and an array of warring factions in the West Wing knocked the administration off balance on an almost daily basis — because Trump's decisions would shift wildly depending on the last person to talk to him. Now, in John Kelly, Trump has a strong chief of staff, and the result is somewhat more constancy. But the stability has been purchased at a distressing cost.

The fact is that it is Kelly, and not the president, who is the decider in the Trump White House. Yes, the president can fire Kelly. And yes, the broad policy agenda of the administration is largely a function of the priorities Trump set during his presidential campaign (which Kelly shows every sign of endorsing). But beyond that, it's hard to imagine a situation in which Kelly would not be able to shape, and even to get away with actively overruling, the president's decisions.

He's already done so, in broad daylight, on multiple occasions — most recently and most dramatically on immigration, when Senate Minority Leader Chuck Schumer (D-N.Y.) believed he had reached a compromise on immigration in conversations with the president only to learn from Kelly later that same night that the terms of the deal were unacceptable. Kelly has also publicly countermanded the president on the border wall, North Korea, and other matters. How many times has he avoided the need for such public corrections of the commander in chief by manipulating information the president sees so as to avoid him taking supposedly unacceptable positions in the first place? That's something we might not know until Trump leaves office, if ever.

This is a much bigger usurpation of presidential authority than what we saw in the final years of the Reagan administration, when the president began to show signs of suffering from Alzheimer's, or even after Woodrow Wilson suffered a debilitating stroke, since each took place when the president was already late in his second term, long after the administration's priorities had been set by the highly functional president himself.

On one level, Kelly's power-grab is comforting. The country has a president who is temperamentally unfit and intellectually ill-suited to office he holds. Given that reality, it's a relief to know that the necessary tasks of governing can go on, and that a presidential temper tantrum against Kim Jong Un is unlikely to issue in a nuclear strike on North Korea (and the subsequent retaliatory strike against the U.S. and its allies).

But on another level, the reality of what's going on in the Trump White House is disturbing. Despite the irregularities of the 2016 election, Donald Trump prevailed — and yet in the decisive respect, he is not the president of the United States. He may hold the office and nominally possess its powers, but John Kelly (a man who did not run for and did not win the presidency) is the one ultimately making the calls.

So much for the efficacy of democracy in America.

Trump is not the decider. Instead, his presidency serves primarily as the focal point for the anger and resentments that got him elected. By serving as a living, breathing, swearing, and tweeting avatar of furious Republican voters, the president manages to keep the administration ideologically centered in the broadest sense. But the endless stream of Trumpian invective also makes liberals apoplectic — a reaction that just as endlessly delights those same Republican voters, who increasingly view politics as a form of full-contact entertainment modeled, metaphorically at least, on the gladiatorial spectacles of ancient Rome.

That's why I partially disagree with Jacob Levy's thoughtful essay about the importance of treating Trump's verbal invective with utmost seriousness and concern, regardless of what policies get enacted during his presidency. The president's words derive their enormous power entirely from how we respond to them. If we react to every ignorant, racist utterance by proclaiming, "Oh my God, can you believe what Trump just tweeted? It's is so terrible and dangerous for the president to talk that way!", then we have played a crucially important role in validating those utterances as terrible and dangerous.

If in the most decisive respect Trump isn't the president, then maybe we need to start treating him a little less like a president and a little more like the demagogic carnival barker he truly is. That doesn't necessarily mean ignoring the vituperation and the tweets. But it might mean responding to them with selective mockery and dismissal instead of constant and continual panic and alarm.